Other celebs in attendance and pictured below: Chuck star Zachary Levi, Eastwick actor Matt Dallas and Joel Moore, who played Katy‘s date in her “Waking Up In Vegas” music video.

After the Willy Wonka and the Chocolate Factory extravaganza, Taylor tweeted, “@Katyperry knows how to throw a birthday party! I would even go as far as to say it was party-licious. Best EVER. Happy bday, pretty girl!!